Method of making dies



Feb. 20, 1934. 1-. F. MITCHELL METHOD OF MAKING DIES Filed' June 17,1931 -INVENTOR 7/10/7105 F/Jzir/w/Z BY HIS ATTORNEM Patented Feb.20,1934

UNITED STATES METHOD OF MAKING DIES Thomas F. Mitchell, Jamaica, N. Y.,assignor to Paris Art Label 00., Inc., New York, N. Y., a corporation ofNew York Application June-17, 1931. Serial No. 545,019

5 Claims.

This invention relates to improvements in the method of making dies.DLes made in accordance with the process hereinafter described areparticularly adapted for use in that depart ment of the printing artwhich relates to embossing or debossing and which includes themanufacture of art labels. I

In the embossed printing art it is necessary to make a die in the formof a reversed replica of the desired art work. The well known copperplate used for making engraved business cardsv and the like representsone form of die of the known art. A copper die or copper plate howeverowing to the softness of the metal of which it is made has a relativelyshort useful life and is unfit for further use after a comparativelysmall number of engraved pieces have been produced. When a die is to beused for embossing or debossing, or for manufacturing art labels it isnecessary to. use greater pressure than when the die is to be used forordinary copper plate engraving and as the required number ofimpressions or reproductions may run into hundreds of thousands a copperplate or die made of copper owing to its short useful life would beentirely unsuited for this purpose and accordingly it has heretoforebeen customary to replace the copper die with one or more steel dies. Asdies must be hand engraved and steel is hard to cut steel dies are veryexpensive to make and increase the ultimate cost of-the art product.When the order is for many thousands of reproductions it is customary tomake a multiple unit consisting of a plurality of dies which can bemounted in a single press to simultaneously produce a plurality ofreproductions so that the output of the operator of the press in anygiven period of time can be multiplied accordingly thereby appreciablyreducing the cost of production insofar as the cost of the labor of thepress operator is concerned, while at the same time increasing the diecost. Obviously it is of great importance in estimating the cost ofproducing any given quantity of art productions to strike a correctbalance between the cost of any given number of dies required and thesaving in wages to be accomplished by the use. thereof. When hand tooledsteel dies are used the cost of the dies increases in direct ratio totheir number and the die must be made from an illustration eonforming insize to the ultimate reproduction so that when the reproduction desiredis small it is very difficult, if not'impossible, to insert much detail,and it is still more difficult for the engraver to reproduce fine detailwork on a steel die. Steel dies have also been made by an etchingprocess employing acid but owing to the time required in the acid bathfor etching steel this process is both slow and costly.

of a die bearing a largely increased amount of detail.

Other objects will appear from the detailed-description which follows:.

In the drawing comprising but a single'sheet of seven figures numberedFigures 1 to 7 inelusive, certain embodiments of the invention are setforth:--

Figure 1 illustrates an art-sketch of the desired reproduction drawn toexact scale;

Figure 2 represents a black and white enlargement of the sketch ofFigure 1;

Figure 3 is a plan view of a'copper die for reproducingan impression ofthe art work of Figure 1 to scale;

Figure 4 is aiplan view of the finished die of Figure 3;

Figure 5 is a l; vertical cross section of the die of Figure 4 takenalong the line 55 of Figure 4 looking in the direction of the arrows;

Figure 6 is a top plan view of a variation; and

Figure 7 is a vertical section taken along the line 7'7 of Figure 6looking in the direction of the arrows.

Like reference characters designate correspending parts throughout theseveral figures of the drawing.

An art sketch 11 (Figure 1) on any form of paper 10 is first made.This'art sketch consisting of a series of characters or symbols 18assembled to produce the desired tout ensemble surrounded with aperipheral line 12 preferably defining a closed figure is preferably ofthe exact size of the ultimate reproduction.

From the art sketch of Figure 1 an enlargement (Figure 2) on a suitablebackground 13 is prepared in black and white the symbols 18 beingarranged to reproduce the tout ensemble 111 surrounded by the peripheralline 112 defining the shape of the die. Figure 2 may be enlarged on anypreferred scale best suited to bringout all of the desired detail.

' If the die is to be in the form of a single unit the black and whiteenlargement of Figure 2 reduced to the size of the ultimate die isphotographically reproduced upon a light sensitive copper plate 14(Figure 3). On the other hand if it is intended to make a multiple unitdie, a

sufficient number of photostatic reproductions of the black and whiteenlargement are made and. said photostats are then placed side by sideso as to occupy a minimum amount of space wherein the finished product(as for example in the manufacture of art labels and seals) the spacebetween dies would be waste material. The photostats thus unitarilyarranged are then photographically reproduced to the size of theultimate die upon a light sensitive copper plate. In any event thecopper plate is now subjected to a photoengraving or photoetchingprocess by being immersed in an acid bath whereby the art work of Figure1 is reversely engraved upon" the copper plate 14. It should beunderstood that while for purposes of illustation only one reproduction11 is disclosed upon the copper plate 14 (Figure 3) any desired numberof reproductions placed for example, base to apex, could be reproducedupon the copper plate 14 the number of reproductions being dependentupon the number of dies to be assembled in the multiple unit die; 7

Afterthe photoengraving process has been completed the die may beprovided with a hand tooled or hand engraved cutting edge 15 (Figure 4)individually surrounding each closed figure if it is intended to be usedfor the manufacture of art labels or seals, while'if it is to be usedfor embossing by a die stamping operation the cutting edge 15 will notbe required. In either event however whether'the cutting edge 15 issupplied or omitted the die 14 is now subjected to an electroplatingprocess for the purpose of covering the surface of the die with anelectrolytically deposited chromium surface 17 (Figure 5) after whichthe die 14 is mounted upon a suitable metal base 16 which may bethreaded as indicated at 19 to permit the dieto be readily mounted in adie stamping press or automatic label press according to the use towhich the die is intended to be put.

It is assumed that the die illustrated in Figures .4 and 5 is intendedto be used for embossing purposes in which event the symbols 18 willdefine recesses in the face of the die 14, while it isassumed that thedie disclosed in Figures 6 and 7 is to be used for debossing purposes inwhich event the symbols 18 will be in raised relief above the surface 14of the die.

The thickness of the chromium plated deposit 17 will vary dependent uponthe amount of detail work carried by the die. Where the detail work isdelicate only a light chromium plate will be applied, whereas when thesymbols are more substantial a heavier chromium plate 17 can be appliedwithout blurring the die. Obviously any detail work no matter howcomplicated which the artist is able to insert in the black and whiteenlargement of Figure 2 will be faithfully reproduced on a reduced scaleduring the photoengraving process and the artist will be able to makealterations and corrections in the black and white enlargement of Figure2 without difiiculty until the tout ensemble is perfectly satisfactory,whereas if the die 14 was made of steel and hand tooled any mistakesmade by the engraver would necessitate the making of an entirely new dieand the more nearly the die was completed whenthe mistake arose thegreater would be the expense involved in eliminating the mistake. V

The die produced by the process described ,herein has all the advantagesof a copper plate as to cost of production and of a steel die as todurability.

While in the embodiment illustrated the die is made of copper platedwith chromium any other inexpensive acid responsive metal might besubstituted for the copper so long as it possesses an electrolyticafiinity for chromium and any other plated steel-like surface might besubstituted for the chromium plated surface 17 so long as thesubstituted metal can be electrolytically deposit- .ed upon the acidresponsive'base 16.

If the die is provided with a cutting edge 15 it can be used in anautomatic label press for cutting out labels, seals, and the like,irrespective as to whether the same are embossed or debossed, while-ifthe die is intended to be used for die stamping purposes, that is, forembossing cards, labels, etc., previously or subsequently cut to size bya separate operation the cutting edge 15 will not be required. It shouldbe understood however, that where the die is intended to be used formaking labels or seals in an automatic label press the cutting edge mustremain sharp at all times as the life of such a die is in effectdetermined by the'life of the cutting edge and the cutting edge can onlybe retained if the die has a hard surface, such as is obtained withsteel or with a chromium plated steel-like surface 17.

What is claimed is:

1. The method of making a die-for an automatic label press whichconsists in delineating the design upon a foundation of relatively softmetal, hand-tooling a raised encircling cutting edge out of said metalabout the peripheral edge of the foundation design, and chromium platingthe foundation design and the cutting edge to provide an exceedinglyhard working surfacejor the die.

2. The method of making a die for an automatic label press whichconsists 'in photo-engraving the detail of the ultimate die upon a softmetal body, hand-tooling a raised encircling cutting edge of said metalabout the peripheral edge of the engraved detail, and uniformlysurfacing said engraved detail and said cutting edge with anelectrolytically deposited coating of chromium.

3. The method of making a die for an automatic label press whichconsists in photo-engraving the die detail upon an acid-responsiverelatively soft metallic foundation, hand-tooling an encircling cuttingedge of said soft metal about the peripheral edge of the engraved die,and superimposing a hard working surface of uniform thickness upon thesoft metal die by electrolytically depositing a layer of chromiumthereon.

4. The method of making a die for an automatic label press whichconsists in photo-engraving the die detail upon a copper foundation,hand-tooling an encircling cutting edge of cop- Iper around theperipheral edge of the die detail,

and reinforcing the die with a hard working surface faithfullyconforming to the surface contour of the die by electrolyticallydepositing a layer of chromium thereon.

5. The method of making a die for an automatic label press whichconsists in preparing an art sketch conforming in size, shape and designto the finished die, enlarging the art sketchand bringing out thedesired detail, photographically reproducing the die in its ultimatesize from said enlargement upon a lightsensitive copper plate,hand-tooling an encircling cutting edge around the die detail, andchromium plating said detail and said cutting edge.

THoms MITCHELL.

